Device for ventilating vehicle chairs

ABSTRACT

A device for ventilating chairs which has an air-permeable covering portion (13, 14) which is applied over the filling (7) of the chair, an insert (15; 59) located between the covering portion and the filling and a suction device (26) which through a system of suction openings in the covering (57, 60) and the insert (40, 56) evacuates the ventilating air. The insert (15) is joined with the covering (9) of the chair to an integrated unit, which is tightened against the filling (7), and from the insert (15) there extends a duct connection (40, 25) tightly separated from the filling, which leads the air to the suction device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device for ventilating a chair, whichis of the kind comprising a cushion with a shaping filling that carriesup and supports a person sitting in the chair and preferably consists ofmoulded plastic foam or similar material, a covering which is appliedover the filling and over an insert located under the covering, theinsert comprising a material which is permeable to air and preferablyelastic and fibrous and being limited by a layer of airtight material.The ventilating device comprises a covering portion which at leastpartly is permeable to air and has such a surface extension that it istouched and loaded by the body of the person sitting in the chair, and asuction device which communicates with the inside of the coveringportion and through a system of suction openings ventilates away the airthat is drawn inwards through the cushion. The system of suctionopenings together with the air-permeable material of the insert,distributes the negative pressure produced by the suction device andthereby the ventilating flow of air.

The invention is specially intended for vehicle chairs, but shall not belimited hereto but can be applied generally in all kinds of sittingfurniture.

2. Description of the Related Art

A ventilating device of the above-stated embodiment is known throughSwedish patent 8703176-1 (Publ-No. 459.389). A layer of fibrous,air-permeable material located between the covering and the filling ofthe chair cushion is, according to the patent, inserted into an airtightbag which also encloses the plastic foam filling of the chair cushion.The bag is also shown containing a second fibrous layer located on theunderside of the filling, where the bag has a connection for a suctionduct.

OBJECTS AND SUMMARY OF THE INVENTION

The ventilating air shall therefore, according to the Swedish patent, bedrawn right through all the parts of material of which the chair cushionis comprised, which irrevocably causes the device to work with a highflow resistance the major portion of which comes from the materialenclosed by the bag, while the minor portion appears in the covering ofthe chair, which is said to consist preferably of woolen fabric. Thehigh resistance that the suction device must overcome limits naturallythe flow of air which in turn causes that the desired cooling effect onthe body of the person sitting in the chair is not obtained. Briefly,the known device is characterized by a low efficiency, counted as theutilized suction effect in relation to the effect supplied to thesuction device.

It is not possible nor desirable, especially in installations invehicles, to compensate the poor cooling effect by choosing a bigger,more powerful suction device, which would give a sufficiently greatventilating flow of air, because that would give a high powerconsumption. A device of this kind must work continuously the whole timewhen the vehicle is driven, and therefore an increased load on itselectric system must be avoided.

A valuable contribution to the development in this area which has beenpresented through the invention according to the above-mentioned patentis the steps disclosed therein to get a uniform distribution of thenegative pressure on the inside of the air-permeable covering portionand thereby a uniform distribution of the flow of air through thiscovering portion. Such a step entails that the suction openings in saidinsert receiving the ventilating air from the covering are arranged in aspecial pattern. The suction openings in the seat part of the chair arepositioned in a U-shape to give a good suction effect on the sides ofthe thighs and seat of the person sitting in the chair, while theopenings in the insert of the backrest follow a line along the symmetryplane of the chair in order that sweating shall not occur on theperson's back. As stated in the patent specification, this causes thatthe suction effect of the device is limited or concentrated to thesurfaces of the covering which are touched by said body parts while asuction effect is avoided in places where it is not needed.

This arrangement will, however, not come to its full advantage in theknown device due to its low efficiency, since the fact that a uniformdistribution of the negative pressure and the flow of air and a suitableconcentration of the suction effect do not improve the cooling effect,if the negative pressure inside the covering and the flow of air throughthe suction openings of the insert are insufficient.

The known device has also other inconveniences, particularly ininstallations in vehicles, due to the extensive contents of the "tight"bag. A cushion of a vehicle chair must be mechanically fastened in thecarrying frame of the chair in which sheet-metal edges, screws and otherprotruding details facing the filling can hardly be avoided. Because thecushion and the bag move in the frame due to vibrations in the vehiclebody and changes in load caused by the vehicle driver or passengers,there is an obvious risk that the sides and bottom of the bag aredamaged, so that part of the air that shall ventilate the chair leaks inand moves through the filling to the suction device. Hereby, the coolingeffect is naturally decreased.

Another inconvenience which also depends on the extensive insert in theknown device is the mutual dependence between the various parts of thecushion that affects their design, manufacture and mounting. Due to thecomplex geometry of the filling used in modern cars to give a goodcomfort to the driver, it is difficult to make the surrounding layer fitthis geometry and the frame of the chair. Modern car seats havefurthermore mechanical fastening devices for the chair cushion whichtogether with hooks fasten to the chair covering so that the latter isstretched downwards towards the frame and forms transverse andlongitudinal folds, which also serve to give a characteristic design tothe chair. To apply these hooks so that they do not cause leakage in theplaces where they pass through the "tight" bag constitutes a problem forthe chair manufacturer. Because the filling shall be entirely covered bythe bag it is furthermore difficult to arrange a tight connection in thebottom of the bag to the suction device, which must be done with thecushion in its place in the chair frame.

The present invention is an improvement of the device known through thepatent SE 8703176-1 and an important object is to eliminate theabove-described disadvantages. It is generally an object of theinvention to give to the device the best possible efficiency, for whichend the lowest total resistance for the ventilating air shall be sought.

While principally maintaining the above-stated advantage of the knowndevice, which relates to the distribution of negative pressure and flowof air, it is a further kindred object to attempt to provide a device inwhich the major portion of the pressure drop appears in the suctionopenings while only a minor part of the pressure drop over the deviceemanates from the cushion material.

One additional object of the invention is to seek to eliminate the riskof leakage in the device so that, if possible, the whole flow of air tothe suction device becomes effective and has a cooling effect on thebody of the person sitting in the chair. The invention also aims at adevice which is easy to build into a vehicle chair or in other sittingfurniture. These purposes and objects are fulfilled in that the deviceaccording to the invention has been given the characteristics stated inthe subsequent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention shall now be described in more detail with reference tothe accompanying drawing. Hereby, as in the claims, certain expressionsregarding position, such as "upper", "lower", "underside" and "at thebottom" which strictly apply to the device in the seat part, will forthe sake of simplicity be used also for the device in the backrest withthe same meaning as "front", "rear", "rear side" and "at the rear". Whenreading the claims and the text relating to FIG. 2 the reader shouldtherefore also regard the section of the backrest as if seen vertically.

FIG. 1 is a side view of a vehicle chair, the seat part and backrest ofwhich are provided with devices according to the invention, which areschematically shown in section;

FIG. 2 is a cross-section of a portion of the backrest taken in itssymmetry plane in the same way as the corresponding section in FIG. 1,but on a larger scale;

FIG. 3 is a cut-out of the device comprised in the seat part accordingto FIG. 1, also shown on a larger scale, and

FIG. 4 is a cut-out seen in perspective of a portion of the deviceaccording to the invention in an alternative embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

To make the drawing clear, the parts in the device which are made ofbedded material are shown with extremely exaggerated thickness.

In FIG. 1, the numeral 1 designates generally a ventilated vehiclechair, here shown as a front chair in a passenger car and comprising aseat part 2 and a backrest 3 which is attached to the chair frame 4 in ajoint 5 so that the backrest can be set in different inclined positions.

By the expressions "vehicle chair" and "chair" here as well as in theclaims it is meant other kinds of chairs and seats used in vehicles thanthe one shown here, such as back seats in cars, seats and chairs inbuses and airplanes, seats and couches in railway cars and passengerships and the armchair-like chairs that are used in for example lorriesand in which the seat part and the backrest form a unit. Office chairsas well as other sitting furniture, which may require ventilation, arealso included in the area of application. Even if the device accordingto the invention is shown and described here in only one kind of vehiclechair, the invention shall not be limited hereto but comprisesapplications in all kinds of chairs or seats which shall be possible toprovide with ventilating devices of the kind that the invention relatesto, in order to improve the comfort of a sitting person.

In the drawing, the numeral 6 is the chair cushion which comprises afilling 7 which usually is hollowed-out with elevated longitudinal sides8 to give a good support to a person sitting in the chair. The fillingcan consist of molded foamed plastic or similar material which with acertain spring can carry up the sitting person. The chair cushion hasfurthermore an enclosing covering 9 whose external layer 10 is ofleather, plastic-coated fabric or textile material and which within hasa layer 11 of soft elastic material that promotes comfort and canconsist of polyester fibres or perforated foamed plastic. A thin webwith wires forming an electric heater 12 can also belong to thecovering.

For the ventilation of the chair, in case the layer 10 consists of atight material, it shall have a perforation on approximately rectangularcovering portions 13, 14, which are limited by the sides 8 of the seatpart and the backrest, respectively, and which are touched and loaded bythe body of the sitting person, and for said purpose there isfurthermore on the underside of these covering portions a plate-formedinsert 15 having an air-permeable material 16, which preferably isfibrous and can consist of horsehair, coconut fibres or syntheticmaterial. The insert furthermore comprises a layer 17 of an airtightmaterial, for example PVC-coated polyamide, which in the embodiment inFIG. 2 like a bag encloses and limits the air-permeable material 16, sothat the insert gets principally the same surface extension as thecovering portions 13 and 14. On its underside the insert 15 has athickening part 18, which as FIG. 1 shows extends from the front alongthe central plane of the chair past transverse folds 19 in the covering,and which serves to ensure that the insert despite the folds gets fullair-permeability.

The insert 15 is so arranged that because of the surrounding edges 20and the undersides 21, 22 of the insert, it fits into a recess in thefilling 7 which forms supporting surfaces 23, 24 against which the layer17 of the insert shall bear tightly. From the latter supporting surfacethere is a conducting connection, which according to the drawing canconsist of a channel 25 extending from the lower layer of the insert toa suction device 26. This is preferably a fan of radial type, attachedat the bottom of the seat part and in the backrest against a bottomplate 27 and a so-called pullmaflex wire-netting 28, respectively, orother carrying means in the frame of the vehicle chair.

The suction device, whose construction is best seen in FIG. 2, has inits central part an electric motor 29 whose jacket is driving andcarries a fan wheel 30. The wheel has a plurality of blades 31 attachedbetween wheel plates which at the periphery form the outlet 32 of thefan, where the air that ventilates the vehicle chair can flow out freelyin all directions.

The fan wheel is enclosed in a case comprised of a lower part 33 onwhich the motor 29 is attached, and an upper part 34 which together withthe jacket of the motor defines the inlet 35 of the suction device. Thecase parts form attachments with which the fan can be mounted at thecarrying means of the chair which in the figure is shown as asheet-metal plate 36 combined with the pullmaflex wire-netting 28. Abovethe fan motor there is a protection plate 37 with openings 38 for theair which is drawn out of the insert 15 and flows to the fan through thechannel 25.

The fan construction, which is no part of the present invention, is theobject of a separate patent application filed simultaneously herewith,entitled "A fan device contained in a ventilated vehicle chair" withpriority from Swedish patent application 9503183-7. Therein, the fan isdescribed in more detail. Typical of the construction is its smallnessin height and thereby the compactness in structure of the suction device26 which makes it possible to install in the backrest without intrudingon the space of the back-seat passengers, as well as in the seat partwhere the space under the chair cushion is very small because of theadjustment means (39 in FIG. 1) which exist in modern car seats for theadjustment of the seat part and backrest.

An alternative to the just described suction device with two separatelyworking fans built into the chair is a single fan mutual for the seatpart and the backrest, which can be located in the seat part. Here, theconducting connection to the fan comprises a suction duct which extendsfrom the backrest via the rear portion of the seat part to the mutualfan, so that in its inlet it will receive all the air drawn out of thetwo inserts 15. The suction duct is suitably formed as a hose, which istightly inserted at an opening in the lower airtight-material layer 17of the backrest, preferably in the thickening part 18 of the insert. Thehose can be invisibly inserted into the filling of the backrest and theseat part and be supported by the carrying means 28 and 27 unto the fanunit, where the hose can end in the channel 25 of the seat part,alternatively be directly connected to the inlet 35 of the fan.

A hose duct to a mutual fan can also come in use in the event a seatpart or a backrest has two or more covering portions separate from eachother, which do not have a single mutual air-permeable insert, but haveseparate inserts or inserted portions only one of which has itsair-permeable material standing in connection with the fan in accordancewith the example of embodiment in the drawing. For the adjacent coveringportion or portions and their inserts or inserted portions, which can beseparated through a fold deep in the cushion, a conducting connection orconnections can be arranged to the inlet of the fan by means of a hose,which is connected in the same way as described above for a backrest.

In another alternative application, which is suitable for vehicles orcraft with a plurality of passanger chairs or seats, such as buses orairplanes, each chair or seat can be connected to a suction device whichis one for the whole vehicle, wherein the fan unit is suitably locatedin a luggage space. Such a location can also be preferred for anapplication of the invention in the backseats of cars. Also in bigluxuriously equipped cars the space under the back seat is so narrowthat a suction device is difficult to install, and a good solution istherefore to lead the ventilating air in a duct, in a way known per se,to a fan mounted in the luggage boot.

Irrespective of what type and what mode of installation of the suctiondevice it is a strong desire that its suction effect result insufficiently high values of negative pressure and flow of air at the topof the inserts 15. According to an important characteristic of theinvention the inserts therefore exclusively comprise a material with anair-permeability which is considerably greater than the foamed plasticin the filling 7, and furthermore it is essential that the connectionbetween the insert and the suction device is without loss, if possible,with no leaks and with a low flow resistance. It shall therefore bepossible to draw the air directly out of the permeable material 16 inthe insert 15 and via conducting means 40 in the underside of the layer17 to lead it further through the channel 25.

To prevent air from leaking to the suction device through pores in thefilling material 7, the device in FIG. 2 according to a specialcharacteristic of the invention has a bellows 41 of rubber or otherelastic material which forms a tight wall in the channel 25. The bellowsstarts at the supporting surface 24 on the filling against which bearsthe tight layer 17 of the insert so that it overlaps and seals the upperflange 42 of the bellows, and extends down to the inlet 35 of thesuction device where the bellows forms partly a double profile 43extending around an edge on the protection plate 37, which profile sealsagainst the sheet-metal plate 36, partly a downwardly directed lip 44which prevents air from leaking radially inwards to the inlet.

An alternative way of preventing leaks from the filling 7 is that,instead of the rubber bellows, the wall of the channel 25 and thesupporting surfaces 23, 24 are provided with an airtight layer 45, seeFIG. 3, which can be applied for example by means of spraying after thefilling has been formed.

According to a primary characteristic of the invention, the covering 9of the chair cushion and the insert 15 forms an integrated unit, whichafter its formation can be tightened against the filling 7. How thisunit is achieved is evident from the cut-out in FIG. 3. The previouslymentioned edges 20 on the insert has a lip 46 formed through theextension at the sides of the airtight layer 17, so that its upper side47 as well as the edge portion 48 of the underside go past theair-permeable material 16 of the insert, the lip tightly sealing theedges of the insert on all four sides of the insert. The lip is alsotightly connected to the external covering material which as the figureshows can be done in a way such that the layer 10 is cut out withsurpluses 49, 50 coming from the above-mentioned covering portions 13and 14 and from the sides 8, respectively, whereupon the ends of the lipand the surpluses are sewn, glued or welded together to a tight, strongseam 51. Alternatively, the edge portion 48 on the underside of thelayer 17 can be made shorter than the extended upper side 47 and with aseparate seam be attached to the upper side so that the lip only getsone airtight layer to be joined with the covering material. Ifpreferred, the latter can be a single piece, which is folded double atthe joining. By folding the covering parts, thus integrated, inwards tothe filling 7, a groove 52 is formed which extends around the coveringportions 13 and 14 and tightly separates these from the surroundingsides 8.

Inside the groove 52, a tunnel 53 of thin fabric can be attached, inwhich tunnel a steel wire 54 is placed so that with the aid of hooks 55attached to the underside of the cushion the covering can be tighteneddownwards so that the insert 15 will have its undersides 21, 22 steadilybearing against the supporting surfaces 23, 24 located in the recess ofthe filling 7. It is realized that, through the above-described steps,leakage is prevented from the filling 7 to the insert 15 and to thechannel 25.

The absence of leakage, together with the low flow resistance of theinsert 15 owing to it exclusively containing air-permeable material,comprehends that the ventilating device gets an improved efficiencywhich makes itself known through increased values on negative pressureand flow of air on the inside of the covering, which values can amountto 350 Pa and 3 to 4 l/s, at which the power consumption of the fanmotor becomes fully acceptable. The object stated in the introduction ofutilizing more effectively the contribution of patent SE 8703176-1relating to distribution of negative pressure and airflow is metherethrough.

For such a distribution, it is to be preferred that in the tight layeron the upper side 47 of the insert 15 facing the covering a number ofsuction openings 56 are made, which are suitably located according tothe previously known patterns of holes, i.e. in U-shape on the seat partand in a row on the backrest. These suction openings, which can have adiameter of about 10 mm, form a ventilating system together with alarger number of small holes 57 in the external layer 10 of thecovering, which holes can have a diameter of 1-2 mm (but shownexaggeratingly big in FIGS. 2 and 3) formed either in that the layer ifconsisting of a tight material is perforated over at least thosesurfaces which form support for the body of the sitting person, orthrough the general air-permeability that the layer has if it consistsof a textile fabric. This system of suction openings, with the goodvalues on negative pressure and airflow that characterize the deviceaccording to this invention, achieves that there is a principally evenand good suction effect on said covering surfaces.

An equivalent but simpler and less expensive variant of the device ofthis invention is illustrated in FIG. 4 which shows a cut-out of apartly air-permeable covering portion 58. Here too, the chair cushioncomprises an insert, designated by 59, which is located between thecovering 9 and the filling 7. The insert has a tight layer 17, whichhere only separates the air-permeable material 16 from the filling,while this material has direct contact with the covering portion. Theinsert shall naturally communicate with a suction device.

Along the surfaces of the covering portion 58 which are known to betouched by the body parts of a sitting person, such as a thigh whosecontours are outlined with dotted-dashed lines in the figure, there areareas with a perforation 60 comprising a great number of holes 61 whichtogether constitute the system of suction openings of the device. Toobtain the sought cooling effect on the body parts in question, it ispreferable that the perforated areas follow the previously knownpattern, i.e. they are executed with rows of holes forming a U-shape onthe seat part and with a linear location on the backrest. Theperforation in the covering distributes hereby the negative pressure andthereby the ventilating flow of air in the same way as described abovewith reference to FIGS. 2-3, i.e. the suction effect is concentrated tothe surfaces from which heat and humidity shall be removed. In case thecomfort material 11 included in the covering is a bright colour whichwould be very visible through the suction openings 60, it may besuitable for aesthetical reasons to apply a thin, darkly coulouredair-permeable web 62, for example of nylon, on the inside of the layer10.

I claim:
 1. A ventilated chair comprising:a cushion with a shapedfilling which is capable of carrying and supporting a person sitting inthe chair, a covering applied over the filling and over an insertlocated inside the covering, which insert is of an air-permeableelastic-material which is limited by a layer of airtight material, and aventilating device comprising 1) a portion of said covering which isair-permeable over at least a portion thereof and which has such asurface extension that it can be touched and loaded by the body of aperson sitting in the chair, and 2) a suction device that communicateswith the inside of said covering portion and that, through a system ofsuction openings, is configured to ventilate away air that is drawninwards through the cushion, wherein the insert has a surface extensionof about the same size as said covering portion, and wherein theairtight layer of the insert is edge-wise joined with the covering toform an integrated unit, which is tightened against supporting surfaceslocated interiorly of the filling, and further comprising duct means,located in the filling and extending from an underside of the insert,for leading the ventilating flow of air coming out of the insert towardsthe suction device, wherein the insert and the duct means aresufficiently airtight to at least substantially prevent air from outsidefrom leaking to the suction device.
 2. A ventilated chair according toclaim 1, wherein the underside of the insert as well as an upper side ofthe insert facing the covering portion are covered by the airtightlayer, and wherein the system of suction openings includes perforationsformed in an upper side of the airtight layer.
 3. A ventilated chairaccording to claim 1, wherein the underside of the insert is covered bythe airtight layer and an upper side of the insert bears directlyagainst the covering portion, and wherein the covering portion hasperforations constituting the system of suction openings.
 4. Aventilated chair according to claim 1, wherein edges of the insertcomprise a lip which is formed from the airtight layer and which extendsaround and past the air-permeable material of the insert, wherein thelip and an additional portion of the covering that is located along theedges of the insert and that is included in both the covering portionand a surrounding covering are folded inwards against one of thesupporting surfaces on the filling to form a groove around the coveringportion, and wherein the lip, the surrounding covering and the coveringportions are joined to one another at a bottom of the groove.
 5. Aventilated chair according to claim 4, further comprising a metal wirethat is located at the bottom of the groove and that hooks theintegrated unit to a frame of the chair.
 6. A ventilated chair accordingto claim 1, wherein said duct means is separated from the filling byairtight wall material, said wall material forming a tight transition toan underside of the airtight layer of the insert.
 7. A ventilated chairaccording to claim 6, wherein the underside of the insert has athickening part which extends along a central plane of the chair andwhich bridges the duct means and contains a channel opening which isconnected to the wall material and which maintains the air-permeabilityof the insert despite folds in the covering portion that compress theinsert.
 8. A ventilated chair according to claim 1, wherein said chaircomprises a vehicle seat.
 9. A ventilated chair comprising:(A) a cushionincluding(1) a shaping filling, (2) a covering which overlies saidfilling, at least a portion of said covering being air-permeable, (3) anair-permeable insert disposed between said filling and said covering,(4) supporting surfaces located within said filling, and (5) a layer ofairtight material located between said insert and said filling; and (B)a ventilating device including(1) a suction device, and (2) at least oneairtight duct which is located, at least in part, in said filling andwhich extends from an underside of said insert to an inlet of saidsuction device, whereina plurality of suction openings are formed withinsaid chair to provide an airflow path leading from said portion of saidcovering, through said insert, and into said duct, wherein said inserthas a surface extension which is of about the same size as said coveringand which is joined edgewise, via said layer of airtight material, withsaid covering to form an integrated unit, and wherein said integratedunit is tightened against said supporting surfaces.
 10. A ventilatedchair according to claim 9, wherein said underside of said insert and anupper side of said insert facing said covering are covered by said layerof airtight material, and wherein said suction openings includeperforations formed in an upper side of said layer of airtight material.11. A ventilated chair according to claim 9, wherein said underside ofsaid insert is covered by said layer of airtight material and an upperside of said insert bears directly against said covering, and whereinsaid portion of said covering has perforations constituting said suctionopenings.
 12. A ventilated chair according to claim 9, wherein edges ofsaid insert comprise a lip which is formed from said layer of airtightmaterial and which extends around and past said insert, wherein said lipand an additional portion of said covering that is located along saidedges of said insert and that is included in both said covering and asurrounding covering are folded inwards against one of said supportingsurfaces on said filling to form a groove, and wherein said lip, saidcovering, said surrounding covering and said additional coveringportion, are joined to one another at a bottom of said groove.
 13. Aventilated chair according to claim 12, further comprising a metal wirethat is located at said bottom of said groove and that hooks saidintegrated unit to a frame of said chair.
 14. A ventilated chairaccording to claim 9, further comprising an airtight wall material whichseparates said duct from said filling and which forms a tight transitionto an underside of said layer of airtight material.
 15. A ventilatedchair according to claim 14, wherein said airtight wall material is oneof a bellows and a layer on a wall of said duct.
 16. A ventilated chairaccording to claim 14, wherein said underside of said insert has athickening part which 1) extends along a central plane of said chair, 2)bridges said duct, and 3) contains a channel opening which communicateswith said wall material and which maintains air-permeability of saidinsert despite folds in said covering that compress said insert.
 17. Aventilated chair according to claim 9, wherein said chair comprises avehicle seat.